Background

Paul Schilder described a severe and fulminating syndrome of acute demyelinating disease in 1912.[1] The original case occurred in a 14-year-old girl who had been healthy prior to the development of papilledema, right hemiparesis, and elevated intracranial pressure. Her neurologic disease followed a course of 4.5 months of deterioration leading to death and ensuing pathological examination of her brain by Schilder. Schilder found 2 large lesions that manifested demyelination with axon sparing. The brain also contained other smaller lesions with a pathology typical for multiple sclerosis.

The exact nature of that child's illness remains controversial. Some have suggested that this child had either acute multiple sclerosis or, less likely, severe acute disseminated encephalomyelitis. The child possibly had some other illness, such as some form of acute fulminant angiopathic or vasculitic illness. The distribution of lesions in this index case (ie, bilateral but slightly asymmetrical large sharply demarcated areas of demyelination) and the resemblance of the pathology to multiple sclerosis (which in turn resembles the pathology of acute disseminated encephalomyelitis) became the hallmarks of the diagnosis of Schilder disease.[2]

Subsequent reports by Schilder (1913 and 1924) included 2 additional patients, each with pathological changes that differed from the other and from the original case.[3, 4] As has been confirmed by reexamination of the pathological features several times in the 1950s, one of these additional patients likely had adrenoleukodystrophy and the other likely had subacute sclerosing panencephalitis. The disease mechanisms and the pathological features of these conditions were unknown at the time that Schilder published his reports.

The considerable controversy and confusion that has ensued has scarcely been dispelled. Although reports of more than 100 subsequent patients thought to be examples of this condition have accumulated in the medical literature in 9 decades, many of these cases may be examples of other illnesses.

In some of these cases, the diagnosis of Schilder disease was based on pathological analysis of the brains of patients who had died from brain degeneration. A smaller number of cases were identified on the basis of analysis of a brain biopsy specimen. The availability of pathological descriptions has permitted many cases to be carefully reconsidered with the benefit of subsequent knowledge of pathological entities unknown to Schilder and to many of the subsequent individuals who have published cases of suspected Schilder disease. This information has permitted the diagnosis of most of these cases to be reassigned to other diseases such as tumor, multiple sclerosis, adrenoleukodystrophy, encephalitis, or subacute sclerosing panencephalitis (SSPE).

Further confusion was generated with the development of CT and MRI technologies. Based upon the appearance of lesions in these imaging studies, a number of cases of supposed Schilder disease have been diagnosed in living individuals, without benefit of pathological analysis of the brain or a brain biopsy specimen. Diagnosis has been made in such cases because of the combination of clinical features and the presence of large white matter lesions on brain imaging.

Many of these individuals with radiographically diagnosed disease have survived much longer than has tended to be the case in individuals whose Schilder disease was diagnosed on the basis of postmortem pathological analysis. Some, indeed, appear to have gone into remission, often in a reduced state of function as compared to their premorbid state but without further exacerbations or progression. Whether such cases represent examples less fulminant forms of Schilder disease or whether postmortem pathological confirmation selects for the most fulminant and lethal forms of Schilder disease is unclear.

The fact that a large number of pathologically diagnosed cases have proven on reanalysis to be examples of diseases other than Schilder disease supports the view that many of these radiologically diagnosed cases are also something other than Schilder disease, such as encephalitis, acute disseminated encephalomyelitis, acute multiple sclerosis, leukodystrophy, SSPE, mitochondrial cytopathies, or other possibilities. A not inconsiderable portion of published reports of patients presumed to have Schilder disease contain too little clinical or pathological information to permit that diagnosis to be confirmed on the basis of modern criteria. Most reported cases have not had testing for adrenoleukodystrophy or SSPE.

Despite all of this confusion, a discrete pathological entity for which one of the various labels subsequently attached to the 1912 variety of Schilder disease may exist. Note that this still remains a pathological entity and that the diagnosis of Schilder disease should remain tentative until such time as it can be pathologically confirmed either by biopsy or postmortem brain analysis. Furthermore, as Charles Poser insisted in attempting to establish diagnostic criteria for Schilder disease, appropriate tests must be performed to exclude SSPE and adrenoleukodystrophy in every case thought to represent Schilder disease.[5]

The small number of cases that Poser or other authorities have been willing to accept as examples of Schilder disease remains a heterogenous collection, and as yet, no understanding of the pathophysiological basis for any of these cases exists. Even among the handful of cases Poser has accepted as examples of Schilder disease, not every case was monitored to postmortem analysis, rendering statements concerning the degenerative potential and lethality of disease tentative.

Although pathologically distinctive, the boundaries between Schilder disease, multiple sclerosis, acute multiple sclerosis, and acute disseminated encephalomyelitis remain unclear. Poser's careful pathologically confirmed 1957 series suggested that at least 70% of cases that have been reported as Schilder disease are examples of multiple sclerosis.[6] This figure was based upon those cases where pathological material remained or where clinical and pathological details were reported in adequate detail for meaningful reanalysis to be undertaken. To these cases he initially assigned the novel diagnosis of transitional sclerosis. He has subsequently chosen simply to describe such cases as multiple sclerosis.

Some of the cases that have been reported as examples of Schilder disease have had onset in the wake of an infection and a course of illness that included deterioration with subsequent improvement and no further recurrence. The sharp margin of demyelination in the large lesions of Schilder disease in some of these cases and the characteristic sparing of the subcortical rim would seem to weigh against acute disseminated encephalomyelitis as the source of these lesions.

However, large lesions may develop in cases of postinfectious or postvaccination acute disseminated encephalomyelitis, and in some instances, these lesions occur in subcortical locations. Furthermore, some of these cases respond quite dramatically to the administration of corticosteroids. These features suggest that the Schilder phenotype can be generated by acute disseminated encephalomyelitis, an entity whose pathological features closely resemble multiple sclerosis.

Diagnosis upon the basis of imaging studies without pathological confirmation increases the likelihood of etiological heterogeneity, including such entities as leukodystrophy, tumor, SSPE, various types of vasculitis, lymphangiomatosis, collagen vascular diseases, nutritional diseases, meningoencephalitis, and other entities in addition to multiple sclerosis and acute disseminated encephalomyelitis.

Poser's careful review of all reported cases has concluded that the medical literature contains no more than 9 definite cases of Schilder diffuse sclerosis of the 1912 type. In agreement with that conclusion, this discussion concentrates on the features of this exceedingly rare disease based upon the features in these 9 individuals. As has been noted, a discussion of the clinical and laboratory features of Schilder disease must perforce remain tentative because the available diagnostic criteria may in one or another respect fail to include or exclude cases appropriately and because the handful of cases that remain for consideration may therefore inadequately reflect the actual nature of this illness.

Indeed, whether this is a discrete illness remains uncertain. These serious uncertainties will not be completely resolved until the time that some specific test for Schilder disease becomes available or progress in the understanding of inflammatory diseases of the brain permits all cases to be parceled out to other diagnostic entities. In the discussion that follows, some consideration is given to 3 other diagnostic categories that overlap with Schilder disease: childhood multiple sclerosis, acute disseminated encephalomyelitis, and those infectious encephalitides for which no specific test exists. The inclusion of some remarks on these categories is necessary because the lack of specific tests make these still incompletely defined categories difficult to exclude and because the boundaries between them and Schilder disease remain incompletely defined.

Specific tests are available for adrenoleukodystrophy, SSPE, and progressive measles panencephalitis, and numerous highly detailed reviews of these diseases are available. Therefore, the reader is encouraged to consult those sources for information concerning the clinical course, laboratory features, and treatment of those important members of the differential diagnosis of Schilder disease.

Pathophysiology

The pathology of those cases that most closely resemble Schilder's original case is characteristic. Widespread demyelination of both cerebral hemispheres with varying degrees of axonal injury is found in autopsied cases. The lesions are usually somewhat asymmetrical, have sharp margins, and spare the immediate subcortical rim of white matter. Similar demyelinative changes are often found in the brainstem and cerebellum. The axonal injury, in the form of Wallerian degeneration, may occur throughout the nervous system, but changes are especially marked in the spinal cord. In severe cases, the pathology thus more closely resembles that of multiple sclerosis than acute disseminated encephalomyelitis.

Some authorities have described cases with characteristic bilateral lesions that are somewhat smaller than those in the foregoing group, lesions that are associated with additional multiple small plaques. The appearance of these plaques more typically resembles the usual multiple sclerosis plaque than typical acute disseminated encephalomyelitis lesions. These cases tend to manifest in adolescence or adulthood rather than childhood, and their clinical course is more variable than the acute severe and more widely disseminated cases.

Epidemiology

Frequency

United States

This disease is exceedingly rare. Excluding more than 100 reported cases as examples of other entities or because the case reports included too little information to be certain, just 9 cases remain in the world's literature. Two additional cases that have been reported since Poser's 1985 review may possibly be included, but neither of these cases fully satisfies the criteria established by Poser.

Mortality/Morbidity

Prior to MRI scanning, diagnosis was only made on postmortem analysis; hence, the cases were regarded as uniformly fatal. Further refinement of the understanding of morbidity and mortality will depend upon diagnostic criteria in the absence of a nonpathological diagnostic test. Death in the reported cases occurred within days to many months.

Race

No information concerning genetic or racial predilection exists.

Sex

Seven of the 9 cases of Schilder disease occurred in boys, all of whom were younger than 10 years. Two additional cases occurred in adolescent or adult women, the adolescent having been Schilder's index report.

Age

Strict definitions of Schilder disease (ie, bilateral large lesions without additional plaques or other findings) results in 7 patients, all boys, whose disease arose chiefly between 7 and 10 years of age. Two additional cases occurred in females older than 13 years.

History

The diagnostic criteria established by Poser in 1985 require 6 elements:[5]

One or 2 roughly symmetrical large plaques are manifest, and if more than 1 is present, 1 should be in each brain hemisphere, chiefly in the centrum semiovale. Plaques are greater than 2 cm in 2 of 3 dimensions.

No other lesions are demonstrable by clinical, paraclinical, or imaging data.

No abnormalities of the peripheral nervous system are demonstrable.

Results of adrenal function studies are normal.

Serum very long chain fatty acids are normal.

Pathological analysis by autopsy or biopsy demonstrates histologic changes consistent with subacute or chronic myelinoclastic diffuse sclerosis, changes which in essence cannot be distinguished from those of multiple sclerosis.

To Poser's criteria could be added the currently available diagnostic tests for early childhood leukodystrophies such as Krabbe or metachromatic leukodystrophies.

Based upon the 9 cases that have satisfied Poser's criteria, the following statements can be made concerning the history that precedes clinical presentation of Schilder disease.

This apparently very rare illness arises more commonly in children than adults.

The onset of illness is typically subacute, although in some cases the onset is more abrupt and occurs in the wake of an infectious illness. Headache, malaise, and fevers of unclear etiology often precede the initial phases of illness.

Physical

No features of the general examination are characteristic features of the presentation of Schilder disease. High fevers, constitutional symptoms, and fulminant initial course suggest such alternative diagnoses as encephalitis.

A wide variety of abnormalities may be found on neurologic examination.

Deafness is common. Other brainstem or cerebellar deficits that are encountered include vertigo; paresis of eye movements, including internuclear ophthalmoplegia and nystagmus; facial palsy; dysarthria; or dysphagia.

Cortical blindness is common, and various field cuts may be found, particularly hemianopsia. Hemiparesis or cortical sensory deficits may be found.

Seizures may occur but are not common. Some patients manifest psychosis.

Extrapyramidal manifestations are rare but have been described.

Findings of variable or uncertain localization include generalized spasticity and incontinence of bowel and bladder function.

Malnutrition and cachexia are commonly reported in the middle or late chronic stages of illness, especially in instances where patients fall to a low level of neurologic function such as a chronic vegetative state.

Causes

The causes of Schilder disease, if it exists as an independent entity, are unknown. Although note evidence for a possible infectious illness at the onset of presumed Schilder disease, the significance of this observation remains unclear. In some reports, latency exists between this initial febrile illness and the subacute onset of Schilder disease. Some of these cases may be examples of acute disseminated encephalomyelitis. Other cases have a fulminant course without such clear distinction between prodrome and onset of the disease process thought to be Schilder disease. Many of these cases may be examples of encephalitis or some metabolic disorder.

Laboratory Studies

No specific features of this disease are revealed on routine laboratory studies.

As has been noted, results of serum very long chain fatty acid studies and adrenal function studies must be proven normal. If the pattern of abnormality of the findings of these studies is consistent, the alternative diagnosis of adrenoleukodystrophy should be made.

EEG and CSF analysis must be undertaken in cases suspected to be examples of Schilder disease. EEG abnormalities such as periodic lateralized epileptiform discharges (PLEDs) suggest the alternative diagnosis of SSPE or progressive rubella panencephalitis. These diagnoses are supported by demonstration of abnormalities on the CSF immune profile, such as oligoclonal bands or elevation of the CSF serum immunoglobulin G (IgG) index or CSF IgG synthetic rate. The diagnosis of either of these entities is confirmed by demonstration of elevated rubeola or rubella titers in CSF.

Every effort should be made to identify a possible infectious cause in acute or fulminant cases. This effort should include viral cultures of CSF, nasal or oropharyngeal secretions, and rectal swab. Acute titers for such infectious agents as brucella; Bartonella; Ebstein-Barr virus; cytomegalovirus; Mycoplasma; herpesviruses I, II, or VI; and other infectious agents should be assayed, depending upon the clinical circumstances.

Imaging Studies

MRI studies should demonstrate 1 or 2 large confluent lesions in the deep white matter, usually the centrum semiovale, that are bright on T2 weighting. Lesions should be at least 2 cm in size in 2 of 3 dimensions.

When 2 lesions are found, 1 lesion should in most cases be located in each hemisphere.

Note that one fairly recent case that may be an example of Schilder disease manifested 2 large lesions in 1 hemisphere and none in the other.

No additional lesions should be observed on imaging of the brain or spinal cord, a circumstance that may imply the presence of multiple sclerosis, acute disseminated encephalomyelitis, or some other alternative diagnosis.

Diagnosis cannot ever be made upon the basis of imaging characteristics alone. MRI findings suggesting the presence of Schilder disease may be most often found in patients with multiple sclerosis. In such cases, in addition to large lesions, smaller multiple sclerosis–like lesions, including black holes, may be found on close inspection, suggesting the diagnosis of what Poser has termed transitional sclerosis rather than diffuse sclerosis. Poser found that most of the cases that have been reported as Schilder disease for which sufficient information is available fall into the transitional sclerosis category, a category that in all likelihood consists almost entirely of cases of multiple sclerosis with the possible inclusion of some cases of acute disseminated encephalomyelitis.

Procedures

Brain biopsy specimens may be required to exclude infection, as well as tumors and vasculitic or other inflammatory processes (eg, primary CNS vasculitis, sarcoidosis, histiocytic lymphangiomatosis). Brain biopsy results cannot be relied upon to distinguish multiple sclerosis from acute disseminated encephalomyelitis.

Lumbar puncture should be performed in all cases, especially in order to obtain measles antibody titers to rule out the alternative diagnosis of SSPE.

In patients with Schilder disease, CSF may be normal or may contain 10-60 monocytic cells (lymphs and monocytes).

Elevation of CSF protein is more frequently encountered in Schilder disease than in multiple sclerosis, but it is seldom higher than 100 mg/dL.

Elevation of CSF IgG is found in 50-60% of cases; prevalence for this abnormality is higher than in acute disseminated encephalomyelitis, lower than in multiple sclerosis or adrenoleukodystrophy, and much lower than is usually found in SSPE.

Very little data exist on the IgG index in Schilder disease. Oligoclonal bands have been found in one case.

Staging

Medical Care

The underlying cause of Schilder disease remains unknown, particularly if limited to those cases that conform to the 1912 type. Implicit in that definition is inexorable disease progression. As has been noted, the definition then applies to approximately 9 of all reported cases. Whether the 1912 type cases are to be considered responsive to corticosteroid treatment and whether such treatment would have rendered moot the progressive nature of the illness that Schilder first defined is unknown.

If any wider definition is applied, particularly one based upon radiographic criteria, then a number of inflammatory illnesses are likely to be included, some of which are treatable. Even with radiographic diagnosis, adrenoleukodystrophy, SSPE, progressive rubella panencephalitis, and those forms of collagen vascular disease and encephalitis that can be excluded by CSF or other laboratory studies are presumably excluded from consideration as examples of diffuse sclerosis (Schilder 1912 type).

Based upon such radiologic diagnosis, the critical approach to treatment is to ascertain whether the lesion is responsive to the administration of high-dose intravenous corticosteroids.

General practice in such cases currently entails methylprednisolone administration of doses of 20-30 mg/kg each morning for each of 3-5 successive mornings, followed by a taper of oral corticosteroids. This treatment may be contraindicated by the possible presence of bacterial infections or the unexcluded possibility of herpetic encephalitis. Administration of corticosteroids should be accompanied by the administration of antacids or histamine (H2) receptor antagonists to reduce the risk for formation of Cushing ulcers. Patients should be monitored for such potential adverse effects as hypersensitivity, gastrointestinal bleeding, hypertension, hyperglycemia, hypokalemia, or opportunistic infection. These problems are seldom encountered.

Response to this form of therapy employing this or similar regimens has been documented in a number of single case reports provided over the past decade. Whether the effectiveness of such therapy is pertinent to consideration of strictly interpreted Schilder disease criteria is unclear. In many of these instances where no pathological information was obtained but response to therapy was beneficial, the underlying problem was likely acute disseminated encephalomyelitis or multiple sclerosis. Response to such therapy could also be noted in certain brain tumors (as has been the authors' experience) emulating Schilder disease and perhaps in other entities.

The addition of brain biopsy excludes such diagnoses as brain tumor, vasculitis, collagen vascular process, or encephalitis by the identification of specific pathological changes. In some instances, aspiration or surgical biopsy of large lesions suggesting Schilder disease has been accomplished, and several of these cases have also been reported during the past decade. In such cases, the pathological changes discerned often resemble either multiple sclerosis or acute disseminated encephalomyelitis; the pathological changes of these entities may be quite difficult if not impossible to distinguish on the basis of brain tissue biopsy.

Where such changes are found, the therapy described above, high doses of intravenous corticosteroids, is likely to prove beneficial, although lesions may recur. Some authorities (chiefly those accustomed to treating multiple sclerosis in adolescents and adults) are confident that recurrence of such lesions is diagnostic of multiple sclerosis. Other authorities, particularly those whose experience is largely limited to management of acute disseminated encephalomyelitis in prepubescent children, are confident that some of these cases may represent recurrent acute disseminated encephalomyelitis, an entity that the former group of authorities usually maintains does not exist.

This controversy is as yet unresolved, as are those controversies attendant upon the establishment of diagnostic boundaries for Schilder disease. However, several practical points can be made concerning treatment of those patients with radiographic findings suggesting Schilder disease (ie, large lesions of the type discussed above) and who have had all other pertinent differential considerations excluded (eg, vasculitic, tumor-related, collagen vascular, metabolic, other forms of illness).

Cases remaining that suggest the possible diagnosis of Schilder disease (diffuse sclerosis, Schilder disease of the 1912 type) or especially of transitional sclerosis (defined by the presence of small multiple sclerosis–like lesions in deep white matter in addition to large lesions) arising in postpubertal individuals should be considered to be multiple sclerosis until proven otherwise. The additional smaller lesions tend not to be found at the gray-white margin or in deep gray nuclei or thalamus. This diagnosis of multiple sclerosis can be supported in many cases by the fact that the CSF IgG index and oligoclonal band studies are frequently positive.

Many of these cases appear to respond favorably to intravenous steroid therapy, although their subsequent course is likely to be one of continued development of bouts of multiple sclerosis or the assumption of a progressive form of multiple sclerosis. In such cases, consideration must be given to treatment with immunomodulatory agents.[7] That form of treatment is beyond the scope of Schilder disease proper and is not further considered here. Details are available in Multiple Sclerosis.

Cases arising in prepubertal individuals with imaging findings suggestive of Schilder disease, for whom the alternative diagnoses noted above have been excluded (by specific tests), are likely to have an illness that falls within the family of acute disseminated encephalomyelitis. In some of these cases, smaller lesions are found in addition to the 1 or 2 large lesions that raise the possibility of a diagnosis of Schilder disease. In distinction to the group of adults just discussed, these additional lesions tend to be centripetal within the brain, some of them overlying the gray-white margin, and some may be found in deep gray nuclei or the thalamus.

The findings on CSF immune profile studies such as IgG index and oligoclonal bands are usually negative in these patients, although the myelin basic protein assay is frequently elevated. These patients tend to respond very well to a course of high-dose corticosteroids after the fashion discussed above. They may show resolution of illness, in some cases marked by the complete disappearance of large lesions, even those that appear to show central necrosis. Their subsequent course may include one or more recurrences, and in rare instances, the recurrence may be in the spinal cord (particularly the cervical spinal cord) rather than in the brain.

The best way to set either of the previously mentioned 2 groups apart from the largest number of alternative inflammatory, metabolic, or infectious diagnoses is brain biopsy. In some cases from either of the aforementioned groups, the opportunity for aspiration or biopsy is provided by attempts to reduce the volume of such lesions where they are thought to produce significant elevation of intracranial pressure. In a few such cases, intervention has been determined to be beneficial to the patient. In such cases, alternative diagnoses having been excluded, the pathology may be consistent with either multiple sclerosis or acute disseminated encephalomyelitis, entities that are in fact difficult to distinguish on the basis of a biopsy specimen from a single lesion.

In addition to cases that represent either multiple sclerosis or acute disseminated encephalomyelitis but are not found to have any of the alternative diagnoses noted above, the possibility remains that a very rare and small group of patients have a discrete disease that should be termed diffuse sclerosis (Schilder disease 1912 type). The efficacy of various treatment interventions and prognosis remains unclear.

In addition to treatment with corticosteroids, medical management entails support for breathing, circulation, nutrition, and attention to maintaining normal metabolic profiles during the acute phase of illness. Management includes in fulminant cases prevention of the development of skin breakdown or ulceration or of nosocomial infection from intravenous lines or other sources.

Surgical Care

Neurosurgical care may be required for obtaining a lesion biopsy. In some reported instances, neurosurgical aspiration of large lesions suggesting Schilder disease, particularly those with what appears to be central necrosis, has been judged valuable for both diagnostic purposes and alleviation of pressure.

Consultations

Consultations may be required from infectious disease specialists, rheumatologists, child neurologists, specialists in the diagnosis and management of multiple sclerosis, neurosurgeons, intensivists, and various therapists.

Diet

No specific diet is indicated for patients with Schilder disease. Those who appear to have Schilder disease but are found instead to have adrenoleukodystrophy have been treated with dietary modifications, the efficacy of which remains uncertain. Consideration of this topic is beyond the scope of this review.

Activity

No specific limitations to activity exist. Patients who are thought likely to have transitional sclerosis, and therefore are likely to have multiple sclerosis, may experience exacerbations of symptoms of illness because of exposure to heat, poor nutrition, or because they become overtired.

Medication Summary

The use of methylprednisolone, its indications, and its possible effects have been reviewed in Treatment. Other corticosteroids or intravenous gamma globulin (IVIG) possibly would also prove beneficial during the acute phase of presentation, but no information exists at present upon which to base any but the most general statements concerning these approaches. Whether intravenous corticosteroid therapy should be followed by an oral taper is unclear, although in most instances of recognized Schilderlike disease, such a taper is generally undertaken. No information exists concerning the appropriate length of such a taper or the influence of such a taper on outcome. No information exists concerning the efficacy of immunomodulatory therapy in Schilder disease as defined by the strict 1912-type criteria posed by CM Poser.

Further Inpatient Care

Inpatient & Outpatient Medications

Patients who have received intravenous methylprednisolone should generally receive oral methylprednisolone for a period of 6 weeks, during which time they are tapered from an initial daily dose to every-other-day doses over 3 weeks and then the remaining alternate-day dose is tapered over the ensuing 3 weeks. The initial dose is 2 mg/kg/d or a maximum daily dose of 60-80 mg/kg/d. This taper may be prolonged as needed for patients who demonstrate recurrence of such symptoms and signs of illness as may have resolved during intravenous treatment. The enteral doses may be administered by nasogastric tube or other feeding tubes if the neurologic condition of the patient does not permit the doses to be swallowed. Coadministration of antacids or of histamine (H2) blockers is prudent during the entire course of corticosteroid therapy.

Patients must be monitored for such possible complications of corticosteroid therapy as hypertension, gastrointestinal hemorrhage, hypokalemia, hyperglycemia, and opportunistic infection.

Deterrence/Prevention

Complications

Complications include cerebral herniation, inexorable progression of disease to death, development of pneumonia, sepsis, pulmonary embolization, skin breakdown and ulceration in individuals who are moribund, and the various complications due to corticosteroid administration noted above.

Prognosis

Prognosis depends upon definition of illness. In the current state of knowledge, determining the duration of disease, rate of progression, and outcome from the strictly defined category of diffuse sclerosis (Schilder disease 1912 type) that includes approximately 9 cases is impossible. This is also true because potentially valuable therapies such as intravenous high-dose corticosteroids have not been subjected to carefully designed trials in these cases.

In those individuals who have been reported as having Schilder disease but whom Poser has placed into the category of transitional sclerosis, the outlook derived from 70 cases Poser reported in 1957 demonstrated mean duration of survival to be 6.2 years after onset (range 3 d to 45 y). Disease duration was less than 1 year in as many as 40% of cases, but survival times of at least 10 years were experienced in more than 23%. These cases are in all likelihood examples of an often aggressive form of multiple sclerosis, hence the survival of these individuals tends on average to be shorter than that experienced by most individuals with multiple sclerosis.

In those prepubertal cases with a good response to intravenous corticosteroids, and particularly those who are found to have smaller lesions in locations typical for acute disseminated encephalomyelitis (eg, cortical ribbon, deep gray nuclei, thalamus), a better prognosis may be found in some cases. Information concerning this group and the potential of corticosteroids for remediation of illness is limited. The authors have encountered a small number of patients with large lesions who have had recurrent bouts of illness that have proven difficult to prevent and for whom, despite survival times for as long as 5 years without many cumulative deficits, the prognosis remains guarded.